The Islamist group Ansaru has claimed responsibility for the kidnapping of seven foreigners in northern Nigeria.

In a statement Monday, the group said it has "the custody of seven persons, which include Lebanese and their European counterparts working with Setraco," a Lebanese-owned construction company.

The workers were taken hostage late Saturday, when gunmen stormed a construction site in the town of Jama'are, in Bauchi state. The attackers killed a security guard before fleeing with their captives.

Police say the kidnapped workers include four Lebanese and nationals from Britain, Italy and Greece.

Ansaru previously claimed responsibility for the abduction of a French national in December.

Not much is known about the group. Some analysts believe it has links to Boko Haram, an Islamist militant sect blamed for more than 1,000 deaths in northern Nigeria since 2009.

Britain proclaimed Ansaru a terrorist group last year, saying the group is against the West and the Nigerian government, and has links with al-Qaida.

In its note Monday, Ansaru said the kidnappings were motivated by transgressions against Islam by European Union, in countries such as Afghanistan and Mali.